crankshaft/doc/14_densify.md

1.4 KiB

Densify function

Iterative densification of a set of scattered points using Delaunay triangulation. The new points are located at the centroids of the grid cells and have as assigned value the barycentric average value of the cell's vertex.

CDB_Densify(geomin geometry[], colin numeric[], iterations integer)

Arguments

Name Type Description
geomin geometry[] Array of points geometries
colin numeric[] Array of points' values
iterations integer Number of iterations

Returns

Returns a table object

Name Type Description
geomout geometry Geometries of new dataset of points
colout numeric Values of points

Example Usage

WITH data as (
    SELECT
        ARRAY[7.0,8.0,1.0,2.0,3.0,5.0,6.0,4.0] as colin,
        ARRAY[
            ST_GeomFromText('POINT(2.1744 41.4036)'),
            ST_GeomFromText('POINT(2.1228 41.3809)'),
            ST_GeomFromText('POINT(2.1511 41.3742)'),
            ST_GeomFromText('POINT(2.1528 41.4136)'),
            ST_GeomFromText('POINT(2.165 41.3917)'),
            ST_GeomFromText('POINT(2.1498 41.3713)'),
            ST_GeomFromText('POINT(2.1533 41.3683)'),
            ST_GeomFromText('POINT(2.131386 41.413998)')
        ] as geomin
)
SELECT cdb_crankshaft.CDB_Densify(geomin, colin, 2)
FROM data